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APPENDIX, 



Description of the Bones found in a " Pictfs House" in the 

 Island of Harris. Being Notes to Communication read 

 22d February 1860. By James M'Bain, M.D., R.N. 



The first fragment is a portion of the right side of the upper 

 jaw of a dog of tolerably large size, with a part of the molar 

 bone attached ; the sectorial tooth and first tuberculatecl per= 

 manent molar remain in situ ; and there are sockets for the 

 second and third premolars in front, with a socket for the last 

 true molar behind. The sectorial tooth in the upper jaw of 

 the Canido3 is preceded by a deciduous tooth, and is therefore 

 a premolar. The foramena present in this fragment are the 

 inferior orbital foramen, the lachrymal canal, the spheno- 

 palatine foramen for transmitting nerves and vessels to the 

 nasal fossae, and a slightly developed palato-maxillary canal, 

 The next specimen also belongs to the dog, and is a part of 

 the left lower jaw; it corresponds in size with the portion of 

 the upper jaw just described, and probably belonged to the 

 same individual — it contains the last premolar, the sectorial 

 tooth, the second true molar, and a socket for the third and last 

 permanent molar. The sectorial tooth in the lower jaw is not 

 preceded by a milk tooth as in the upper jaw^ and is in fact 

 the first true molar. The dental formula of the Canidce 



is i 5 — \ c \ — J pm \ — ~ m \ — \ = 42. The depression formed 



by the Masseter muscle in the lower jaw of the dog does not 

 extend to the under edge of the bone as it does in the fox, 

 and would enable the comparative anatomist to distinguish 

 to which of the species this fragment of the lower jaw belonged. 

 The third specimen is the left tympanic bulla of the common 

 seal (Calocephalus vitulinus), broken off at the fissure that 

 divides the bulla from the mastoid process. The mastoid pro- 

 cess is very slightly developed in the section of the Phocidce 



